5meter Humber sib pressure

[Martin]

A bit of confusion of floor types there guys by the looks, so easily done but could be catastrophic for the unknowing reader.

[mattswan2512]

Sorry gurnard your right i meant 0.35 for the centre keel. Not 0.85. As a ali floor honwave owner of the past myself (had her 2 years) i know about the keel pressure. My bad i apologise.

[The Gurnard]

No apology required Matt..you did nothing wrong. I hope I didn’t appear as a Nerd by adding my post..it was only to stop a thread drifting off course.

I spent half my life pressurising telecoms equipment so could instantly “visualise” that 12 psi (0.85 bar) was clearly way too much for a keel. Although I worked with pressure ..I still have to double check figures myself.. as I tend to think of Tyre pressure in PSI and other pressures in millibar and not in BAR.

A bit like Douglas my brother who talks about boat speed in KM/hour.. others in Knots per hour .. and I stick to miles per hour ..simply because I can judge MPH but not KM/HR..and Im not really a nautical man ... so knots tend to tie me up too

So it was a very easy error.. in fact.. Chris started the drift by calling an airfloor a keel. I though of responding then but he had mentioned T38 etc which I presumed others would notice was airfloors he was meaning.

So no harm done..unless Captain Cod is still on a path to the moon .. sitting astride a high powered missile in the shape of an inflatable boat keel .

[Captain cod]

No trip to space for me unfortunately I've got the tubes set at 3.6psI and the keel set at 5psi and they seem the same firmness as pugwash2's hornwave. So I'll see how it goes at ullswater

[chris moody]

Yes, my fault for using the wrong term. I said high pressure keel when I meant high pressure airfloor. Oops.

So it was a very easy error.. in fact.. Chris started the drift by calling an airfloor a keel. I though of responding then but he had mentioned T38 etc which I presumed others would notice was airfloors he was meaning.

[Captain cod]

I'm still very confused . I just recived an email from humber with a manual they say is for there ribs and sibs.it says the tubes should be inflated to between 2psi and 3psi. But I was under the impression that a ribs tubes didn't need to be as high pressure as a sibs because they get there main strength from the floor. Where as a sib gets its strength from the tubes. I wouldn't have thought 2.5psi was enough? ???

[Captain cod]

Here is part of the manual from humber

[Paul]

Captain Cod
I'm inclined to agree with your theory and suspect the manual supplied to you from Humber refers to their rib range not sibs as there's no reference to the keel pressure
Remember that once you've launched your boat the water temperature will influence the air temperatures within the chambers thus lowering the pressure further therefore I'd inflate to 0.25bar (3.6psi) in the knowledge it'll drop anyhow
That's my 2p .... anyone else's input

[Captain cod]

Screenshot of the email I got from them. It's says the manual is for both ribs and sibs but I think they must have got things mixed up because as Paul said there is no mention of the keel. I'll send another email querying it

[harrison]

I agree, those pressures from Humber can only refer to ribs, far to low for any sib.
In the absence of a manual or any sensible advice from Humber I would inflate both tubes and keel to 0.24bar/3.5psi, which is common for quite a few makes, and see how it performs. If performance not right, some manufacturers increase keel pressure to around 0.35bar/5psi, so would treat this as an absolute max.
Good luck.